Magneto-optical recording medium

1. A magneto-optical recording medium in a near-field optical storage system wherein a flying optical head is suspended over said medium by a cushion of gas, comprising: a magneto-optical recording layer including at least one recording track for magneto-optical recording of information; at least one tracking feature associated with the at least one recording track; an upper transparent dielectric layer atop the magneto-optical layer, the upper transparent dielectric layer leveling the at least one recording track and having an upper surface substantially planar over a recordable area of the medium above the at least one recording track and the at least one tracking feature, the upper surface of the upper transparent dielectric layer substantially forming an upper flat medium surface over said recordable area; a reflector layer below the magneto-optical layer; a base substrate below the reflector layer; and a lower transparent dielectric layer below the magneto-optical recording layer, wherein the reflector layer is below the lower transparent dielectric layer, wherein the lower dielectric layer comprises a high index dielectric material, and wherein the upper dielectric layer comprises a first sublayer of low index dielectric material and a second sublayer of high index dielectric material.

2. The medium of claim 1 wherein a thickness between an upper surface of the at least one recording track and the upper surface of the upper transparent dielectric layer is between approximately 100 and 1 m.

3. The medium of claim 1 formed as a disk.

4. The medium of claim 3 wherein the at least one recording track and the at least one tracking feature each comprise annular features.

5. The medium of claim 1 wherein the at least one tracking feature each comprises a depression formed in an upper surface of at least one of: the substrate; the reflector layer; the lower transparent dielectric layer; and the magneto-optical recording layer.

6. The medium of claim 1 wherein the at least one tracking feature each comprises a depression formed in an upper surface of at least one of: the substrate; the reflector layer; and the magneto-optical recording layer.

7. The medium of claim 5 wherein the depression is formed by a groove in an upper surface of the substrate, the groove propagating the depression upward through the reflector layer, the lower transparent dielectric layer and the magneto-optical recording layer.

8. A magneto-optical recording medium in a near-field optical storage system wherein a flying optical head is suspended over said medium by a cushion of gas, comprising: a magneto-optical recording layer including at least one recording track for magneto-optical recording of information; at least one tracking feature associated with the at least one recording track; an upper transparent dielectric layer atop the magneto-optical layer, the upper transparent dielectric layer leveling the at least one recording track and having an upper surface substantially planar over a recordable area of the medium above the at least one recording track and the at least one tracking feature, the upper surface of the upper transparent dielectric layer substantially forming an upper flat medium surface over said recordable area; a reflector layer below the magneto-optical layer; a base substrate below the reflector layer; and a lower transparent dielectric layer below the magneto-optical recording layer, wherein the reflector layer is below the lower transparent dielectric layer, and wherein: the lower dielectric layer comprises a first sublayer of low index dielectric material and a second sublayer of high index dielectric material; and the upper dielectric layer comprises a high index dielectric material.

9. The medium of claim 1 wherein: the upper dielectric layer comprises a first sublayer of low index dielectric material and a second sublayer of high index dielectric material.

10. The medium of claim 1 wherein the reflector layer is metallic.

11. A magneto-optical recording medium in a near-field optical storage system wherein a flying optical head having an air-bearing surface is suspended over said medium, comprising: a base substrate having an upper surface having at least one groove; a reflector layer formed having a lower surface atop the upper surface of the base substrate, the reflector layer further having an upper surface having at least one depression above the at least one groove; a first dielectric layer formed having a lower surface atop the upper surface of the reflector layer, the first dielectric layer further having an upper surface having at least one depression above the at least one groove; a magneto-optical recording layer formed having a lower surface atop the upper surface of the first dielectric layer, the magneto-optical recording layer further having an upper surface having at least one depression above the at least one groove; and a second dielectric layer formed having a lower surface atop the upper surface of the magneto-optical recording layer for interfacing with the flying optical head and having an upper surface substantially flat for presenting the flying optical head with a substantially uniform cushion of air between the upper surface of the second dielectric layer and the air bearing surface of the flying optical head, wherein: said first dielectric layer comprises a high index dielectric material: and said second dielectric layer comprises a first sublayer of low index dielectric material and a second sublayer of high index dielectric material.

12. The medium of claim 11 , wherein: the high index dielectric material of the second sublayer is silicon nitride; the low index dielectric material of the first sublayer is a silicon oxide; and the magneto-optic layer is made of a rare earth-transition metal compound including TbFeCo.

13. A magneto-optical recording medium in a near-field optical storage system wherein a flying optical head having an air-bearing surface is suspended over said medium, comprising: a base substrate having an upper surface having at least one groove; a reflector layer formed having a lower surface atop the upper surface of the base substrate, the reflector layer further having an upper surface having at least one depression above the at least one groove; a first dielectric layer formed having a lower surface atop the upper surface of the reflector layer, the first dielectric layer further having an upper surface having at least one depression above the at least one groove; a magneto-optical recording layer formed having a lower surface atop the upper surface of the first dielectric layer, the magneto-optical recording layer further having an upper surface having at least one depression above the at least one groove; and a second dielectric layer formed having a lower surface atop the upper surface of the magneto-optical recording layer for interfacing with the flying optical head and having an upper surface substantially flat for presenting the flying optical head with a substantially uniform cushion of air between the upper surface of the second dielectric layer and the air bearing surface of the flying optical head, wherein said at least one groove has a groove width and a groove separation, a ratio of the groove width to groove separation being less than about 7:15.

14. A magneto-optical recording medium in a near-field optical storage system wherein a flying optical head having an air-bearing surface is suspended over said medium, comprising: a base substrate having an upper surface having at least one groove; a reflector layer formed having a lower surface atop the upper surface of the base substrate, the reflector layer further having an upper surface having at least one depression above the at least one groove; a first dielectric layer formed having a lower surface atop the upper surface of the reflector layer, the first dielectric layer further having an upper surface having at least one depression above the at least one groove; a magneto-optical recording layer formed having a lower surface atop the upper surface of the first dielectric layer, the magneto-optical recording layer further having an upper surface having at least one depression above the at least one groove; and a second dielectric layer formed having a lower surface atop the upper surface of the magneto-optical recording layer for interfacing with the flying optical head and having an upper surface substantially flat for presenting the flying optical head with a substantially uniform cushion of air between the upper surface of the second dielectric layer and the air bearing surface of the flying optical head, wherein said at least one groove has a groove width being less than about 0175 m.